Boom assemblies are commonly used on agricultural vehicles or towed implements (e.g., sprayers or planters, etc.) to dispense seed, fertilizer, insecticide, herbicide, etc. and other miscellaneous agricultural materials. The typical boom assembly is configured to pivot or fold between operative and inoperative positions relative to the boom support vehicle. In its operative position, the boom assembly commonly extends in a laterally outward direction from the boom support vehicles up to a distance of ninety-feet or larger such that the agricultural applicator covers a large surface area with each pass across a field. The weight of the boom assembly generally correlates with its operative length.
Upon completing distribution of the agricultural materials to the field, a conventional lift mechanism (e.g., manual, hydraulic, pneumatic, etc.) is employed in a known manner to raise each of the booms to a raised, inoperative position. Once raised, manually or automatically operated pivot mechanisms (e.g. hydraulic, pneumatic, etc.) are employed to swing, pivot or fold each of the booms to a folded position for transport. The preferred folded position of the boom assembly is generally parallel to the direction of travel of the support vehicle such that each of the booms and the support vehicle has a narrow profile for ready transport from the field to a roadway.
When moved to a folded, stowed position for transport, typical sprayers use various means and methods to positively lock the lift mechanism associated with moving the boom assemblies from the lowered, operative position to the raised, inoperative position. Operators desire the lift mechanism to be positively locked so that the booms are safely secured in the raised, inoperative position in the event of a mechanism failure during travel on the roadway. A certain known lock assembly uses a pilot-operated check valve mounted at a lift cylinder associated with a hydraulic lift mechanism for moving the booms. Another known lock assembly utilizes a hydraulically-actuated mechanical lock. Yet, still another lock assembly includes resting points or seats located at both the front and rear of each boom and configured to secure the booms in case of failure of the lift mechanism.
However, these certain known lock assemblies employed to secure the position of the lift linkage and supported boom assembly have drawbacks. For example, the above-described hydraulically piloted or actuated lock assemblies can be costly. In regard to the resting structures, providing a resting point structure at the rear of the boom adds undesirable weight and complexity to the design of the towed implement or vehicle.
Therefore, there is a need or desire for a low-cost locking assembly that is overcomes the foregoing difficulties and drawbacks of the prior art. The lock assembly should also be simple and reliable to operate and economical to manufacture. In addition, the lock assembly should be configured to be utilized with a wide variety of vehicles or towed implements in addition to those related to agriculture.